Who is the historical prototype of Li Junxian in the TV series The Legend of Wu Mei Niang?

Li Junxian in the TV series "The Legend of Wu Mei Niang" does exist in history, originally named Li Junxian. But he is just a general around Tang Taizong, not the descendant of his brother Li described in the play.

In the play, Wu Meiniang and Li Junxian were originally a pair of congenial lovers, but Wu Meiniang was mistaken as a gifted scholar of Emperor Taizong and Li Shimin because a portrait entered the palace, and the latter two went to war by chance. Finally, Wu Zetian replaced Li's descendants and died because of her. But the story is just a story after all. In real history, it is impossible for Wu Meiniang and Li Junxian to fall in love, let alone grow up together as childhood friends.

As it turns out, the main gap between Li Junxian and Wu Meiniang is age. Although they lived in the same period, according to the existing historical data, Wu Meiniang was not born when Li Junxian and Li Shimin were fighting on the battlefield. Later, after Li Shimin ascended the throne, Li Junxian became famous, while Wu Meiniang was just born when he was promoted to a knight. How can they grow together? Why can't they talk?

Of course, you may say that as long as two people are willing to love each other, age is not a problem at all! Wu Meiniang finally became the concubine of Emperor Taizong. That's true, but everyone's childhood dreams will be broken. They really didn't intersect, and as early as when Wu Zetian was a girl, Li Junxian had already died, or died in Wu Meiniang.

Once, a fortune teller told Emperor Taizong something to the effect that someone related to Wu would take his place in the future, and his nickname was "Fifth Lady". So Emperor Taizong ordered the execution of Li Junxian and Li Junxian.